This document discusses ways to improve PID controller performance. It begins with an overview of PID controllers and their limitations, then discusses methods for enhancement including upgrading hardware for higher loop rates, improving PID algorithms with techniques like feedforward and gain scheduling, and implementing more advanced controllers like model predictive control. The document provides examples and suggests a process for developing advanced controllers.

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2. How to Improve your PID Controller
Javier Gutierrez
LabVIEW Product Marketing
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3. Benefits of Advanced Control and Tuning
Model-based Manual
• A poorly tuned control control < 1% control
valve costs additional
$880/year*
• A bad pH loop incurred
chemical waste of
$50,000/month*
• A bad kiln temp loop cost
$30,000/month* PID needs
PID is fine
manual tuning
*Sources: Cybosoft and ExperTune
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4. Agenda
• What is PID?
• How to improve performance
 Hardware considerations
 Upgrade PID Algorithm
 Advanced Controllers
• Conclusion
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5. Agenda
• What is PID?
• How to improve performance
 Hardware considerations
 Upgrade PID Algorithm
 Advanced Controllers
• Conclusion
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6. What is PID
• Set Point (SP) – Desired control point
• Output (OP) – Controller output
• Process Variable (PV) – Plant/process output
• Error = SP - PV
error OP
SP PV
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7. PID Parameters
• Proportional
 Drive to setpoint
 Error → 0, OP → 0
 “Steady-state error”
• Integral
 Eliminate steady state error
 OP proportional to ∫ error
• Derivative
 Increase response rate
 OP proportional to rate of change of error
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8. System to control
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9. PID Implementation Demo
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10. PID Control – Pros and Cons
• Advantages
 Proven
 Easy to implement
• Disadvantages
 Not easy to tune
 Not suitable for all systems
• Backlash, friction, and so on
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11. Agenda
• What is PID?
• How to improve performance
 Hardware considerations
 Upgrade PID Algorithm
 Advanced Controllers
• Conclusion
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12. How to program PID
Function Blocks
Windows/Real Time
FPGA Control and Simulation
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13. Benefits of Higher Loop Rates
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14. PID Loop rates
1 MHz
100 kHz
25 kHz
600 Hz
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15. Die Casting Machine
The movement of the aluminium injection plunger controlled in a steady
closed loop at a speed varying from 0 up to 10 m/sec.
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Copyright 2007 © EUROelectronics srl – ITALY -

16. Agenda
• What is PID?
• How to improve performance
 Hardware considerations
 Improve PID Algorithm
 Advanced Controllers
• Conclusion
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17. Upgrade your PID
Disturbances Feed-forward
Non Linear Gain Scheduling
Time Variant Adaptive PID
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18. Feed-Forward
• Commonly used to compensate for a
measurable external disturbance before it affects
a controlled variable.
• e.g. product feed rate changes
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19. Gain Scheduling
• Used to change gain on real-time depending on
OV.
• Bumpless transfers
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20. Adaptive PID
• Mixed of On-Line system identification and
common PID control.
• Can handle time-variant systems
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21. Agenda
• What is PID?
• How to improve performance
 Hardware considerations
 Upgrade PID Algorithm
 Advanced Controllers
• Conclusion
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22. Advanced Controllers
National Instruments
• Optimal Controllers (LQR, LQG)
• Model Predictive Control (MPC)
• Kalman Filters
• Fuzzy Logic
Third Party Partners
• Neural Networks
• Genetic Algorithms
• Model Free Adaptive
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23. How to create an advanced Controller
Control Design
• Datalogging • Deployment
• System • Design • Test
Identification • Simulation
• Model Validation
Plant Modeling Implementation
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24. Temp Chamber - Experiment
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25. Plant Modeling - Validation
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26. MPC Control Design
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27. MPC Control Prototype
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28. Advanced Controllers
• Pros/Cons
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29. Agenda
• What is PID?
• How to improve performance
 Hardware considerations
 Upgrade PID Algorithm
 Advanced Controllers
• Conclusion
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30. Conclusions
• PID
• Consider
 Upgrading hardware
 Enhance PID Algorithm
 Upgrading Control Algorithm
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